New computer (doen't work in the office!)

So on Thursday morning I went to a computer shop and bought a new notebook computer. Brought it home, and had almost finished setting it up (downloading and installing software and stuff) when it blue screened, and after that it just kept blue screening over and over again, before I could even log in. So I took it back to the shop, and the guy was pretty confused, and gave me another one. Took it back to the office and started it up, and this one blue screened the first time I started it up, so I took that back too. The guy was confused again, and said they hadn't had this problem with anyone else, and said that maybe it was because of the RAM upgrade the computers had had done, so I got a refund for the upgrade, and took one of the non-upgraded ones home, and exactly the same thing happened! So I took it back, and said I was very disappointed and wanted my money back (pretty much my whole day had been wasted by that stage), and the offered me a better computer for the same price, so I took that back to the office. This computer did exactly the same thing, and by this stage the store was closed. So I was quite angry by this stage, because I had some work I had to get done for the next day.
Anyway, I took it up to my house and tried to start it up again, and it was fine in my house. It also works fine in the church sanctuary, and in the staircase outside the office. But it doesn't work in the office. It makes no sense!
But otherwise it's a really good computer, particularly for the price I paid, and I want to get to the bottom of this, because it doesn't make any sense!